This is an alternative way the ISS could be constructed by using ELV’s. It is a technical discussion and doesn’t go into financial or political aspects. The intent is to show that the shuttle paradigm would not be required to get us where we are at now. This scenario assumes that since there is no shuttle, resources would be available for some launch vehicle and manned spacecraft development in the 80’s and 90’s. These vehicles could have been available in the late 1990’s or even earlier since many shuttle payloads still would have needed to be launched.

Ground rule: The ISS configuration will be similar to the existing plan (ie, same size modules and trusses with the same layout)

Requirements:

1. Titan-IV, NLS, or EELV class booster. Any LV with the capability of approximately 45klb or so to ISS orbit. It will be called ICLV (ISS Construction LV) 2. Crew Transport Vehicle – Apollo derived or OSP, etc. 3. Logistics Transport Vehicle – the CTV modified for cargo or HTV type. Depends on the logistics requirements of the flight. The modified CTV version would be used for return logistics.4. Crew Launch Vehicle - Core of #1 or even purpose built for #2 and #3.5. Service Module with ARAD or OMV – could be derived from #2 but smaller. It provides attitude control, power and some propulsion to a launch package. Just what is needed to bring a launch package from insertion orbit to the ISS6. Russian supplied hardware (Soyuz, Progress) except where designated, is unchanged.7. US ARAD could have been developed in the same time frame since there is a requirement for it, unlike in the shuttle era. 8. All EVA’s are station based. Assembly sequence is adjusted to account for it.9. Modules and trusses (all hardware) are modified to be launched from ELV’s. The trunnions are removed and one end of the modules is modified to mate to the SM and take launch loads. Same with trusses. The ends of the trusses and modules need to be reengineered to allow for module to module and truss to truss mates. Not impossible, just some work10. Most of the assembly elements do not docked to the ISS. They just rendezvous with the station and one of the arms grapples the new piece.

Now the meat of the discussion:

In this scenario, the FGB is not really needed but it is in the ground rules and it has one mod. It carries a shuttle size RMS but with dual end effectors. PDGF’s are on the FGB and SM. Controls are in the FGB

1. FGB launch 2. SM launch, FGB docks with it3. PIRS launch and docks with SM. Early EVA’s are based from here4. Crew launched by Soyuz and mans ISS5. Node 1 is launched by ICLV with SM. It approaches the FGB and is grappled and attached. The EVA’s are then done from the PIRS6. CTV’s can now fly as needed for crew “reinforcement” for assembly or exchange and LTV’s provide logistics and outfitting support 7. Z1 and PMA3 delivered via ICLV. The PMA3 is attached to the Z1 for launch8. P6 on a ICLV9. Lab on a ICLV10. LTV’s with rack11. SSRMS on a ICLV12. airlock on a ICLV13. S0 on a ICLV14. MT and MBS 15. S1 on a ICLV16. and so on

This is just gross overview and there are minor detail issues that are overlooked which would be worked if this was reality.

I invite comments and discussion. I don’t believe that there are any real problems that would invalidate the premise that the shuttle isn’t needed*. Most would be covered by the previous statement.

Of course, if there was no shuttle, the “ISS” design would have been completely different and optimized around the spacecraft and launch vehicles that would be used.

* Additionally, the LTV’s could be used for precursor microgravity missions much like a FOTON.

Jim - 21/2/2008 9:18 AMOf course, if there was no shuttle, the “ISS” design would have been completely different and optimized around the spacecraft and launch vehicles that would be used.

I think this is the crucial point. If we had Saturn V, Ares V, or J-232 (or another 100T-class launcher), the fundamental design of ISS would have been entirely different. If we had only EELV-class launchers, the fundamental design of the modules would have been somewhat different.

Is the point of the discussion what would we have done if Columbia or another similar event had been the end of the STS program and most of the modules had already been built?

As for getting the SSRMS onboard could it not have been launched with Destiny or Quest, under Jim's scenario? Like how the JEM RMS is hitching a ride on Kibo in May on STS-125.

Also, regarding existing modules like Unity, Destiny, et al - couldn't the trunnion pins be attached to a structure with the OMV at the end and the OMV bearing the launch loads? And couldn't future proposed ISS additions (after shuttle retirement) be done in a fashion similar to Jim's scenario? I would think someone's done some studies about that.

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I'll even excitedly look forward to "flags and footprints" and suborbital missions. Just fly...somewhere.

Correct me if I'm wrong but I was always under the impression that the ISS (or some form of space station) was a way to help sell the Shuttle when Apollo was winding down. And that, ultimately, it was cut down to a fraction of what it was originally meant to be. Now if we never had the Shuttle it's interesting to imagine "what if." Would we have concentrated in LEO? If we kept some form of Saturn would the "ISS" have been a base on the moon?

Jim, one thing strike me about your scenario. The ISS would have been constructed faster (and maybe cheaper?) and would have been utilized sooner and for a longer period of time.

Is the point of the discussion what would we have done if Columbia or another similar event had been the end of the STS program and most of the modules had already been built?

This is to show that a shuttle or orbiter is not needed to build stations. It is to show that an RMS, airlock, large crew and payload bay (shuttle paradigm) were not required now and are not required in the future.

with the CEV, people are whing that it isn't as "functional" as the orbiter and keep wanting to stick an arm and airlock on it. They are not needed.

This is to show that a shuttle or orbiter is not needed to build stations. It is to show that an RMS, airlock, large crew and payload bay (shuttle paradigm) were not required now and are not required in the future.

The Russians have certainly proven that those things are not needed. However, I would argue that they are beneficial.

Is the point of the discussion what would we have done if Columbia or another similar event had been the end of the STS program and most of the modules had already been built?

This is to show that a shuttle or orbiter is not needed to build stations. It is to show that an RMS, airlock, large crew and payload bay (shuttle paradigm) were not required now and are not required in the future.

Okay...I thought there were stations built without the Shuttle - none as large as ISS, but isn't it obvious that it's doable if needed?

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with the CEV, people are whing that it isn't as "functional" as the orbiter and keep wanting to stick an arm and airlock on it. They are not needed.

That included me, but not for building stations - for repairing JWST and other such operations, should the need arise, and even then a much smaller total system - a little arm for a single person (more like a fishing rod), not for moving ISS modules around or capturing Hubble. I'm one of the few around here that wants to do more laps in LEO, and I want to do it in a station built by a J-232 without benefit of arms or EVAs for assembly - I certainly agree fully that the Shuttle approach to constructing ISS is not required, and I didn't realize there were people around that think there is no other way to construct a station.

For that matter, if we had kept it as "Space Station Freedom" in a more KSC-friendly orbital inclination and funded ASRM to completion, things would be drastically different as well. C'est la vie.

Granted that a 22° orbital inclination takes less energy to achieve than a 51° inclination, and thus for the same amount of energy that it takes to get to 51° you could lift more mass if you’re living in the 22° world (I think this is the point you are making). And granted that we are stuck with a 51° inclination because of Russian launch restrictions, that said I always thought that there is something to be gained by over-flying a greater percentage of the earth’s surface. It provides for a greater flexibility in doing observations of ecological changes and meteorological tracking. So, although the US was forced to follow the path of the first Proton launch vehicle it hasn’t all been for naught.

Jettisoning the array and replacing it with a new one would have been easier.

One other way I can come up with is to just fold the array so the tear would have been within reach without the OBSS, but this could have damaged the array even further.

But from a technical point of view, the shuttle proved to be an asset.If in the ISS-without-shuttle scenario the array was damaged too much during refolding, it would have required a new solar array and an extra launch.

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Don't ever become a pessimist... a pessimist is correct oftener than an optimist, but an optimist has more fun, and neither can stop the march of events. - Robert Heinlein

That included me, but not for building stations - for repairing JWST and other such operations, should the need arise, and even then a much smaller total system - a little arm for a single person (more like a fishing rod),

I believe the CEV is not needed for those missions. Most spacecraft are not in reach of the CEV or there is no need to waste a manned mission on it (orbital express)

That included me, but not for building stations - for repairing JWST and other such operations, should the need arise, and even then a much smaller total system - a little arm for a single person (more like a fishing rod),

I believe the CEV is not needed for those missions. Most spacecraft are not in reach of the CEV or there is no need to waste a manned mission on it (orbital express)

Skylab and the Russian stations show how a station might look if you design it to be launched on a traditional LV. There can't be any doubt, that space stations can be built without a shuttle type vehicle - it has been done several times. My feeling is, a lot of the station was designed for exactly the reason that this way it could utilize shuttle caps.

One thing: I believe that whatever paradigm you follow when building a station I think the limiting factor at some point will not be mass but volume and size. For some applications you need large structures. One indication to this is the effort Bigelow is putting into the "foldable" paradigm. And it shows that there are other approaches to this than the ISS one.And for large structures a side-mount payload can be a good thing - you don't run into hight restrictions.

As for launching payload and cargo on the same flight: That's a classic case of simple theory and complex practice. You have less "top-level" items on your mission planning sheet with only one launch yet the details, especially regarding safety, have proven to be so much more complex that it eats up all advantages you dreamed up before.

One more thing: We do a lot of shuttle-bashing these days as in "all the bad decisions that were taken back then", "if we only had kept the Saturns" etc. We know that now, but probably we had to go through that experience to learn that the shuttle paradigm does not work. In retrospect you always know better. And don't tell me about people who have said it before. For each and every issue in the world you will find people who have predicted exactly that outcome from the beginning - the point is usually there will be as many who predicted the exact opposite.

Very interesting post...I haven't seen too many people say the ISS couldn't have been built without the shuttle. However, I have seen plenty of comments that we should have abandoned the shuttle immediately after Columbia and just launched everything remaining on Titan IV's. None of these suggestions had any thought put into them, however, like the crew launch vehicles or the modifications to hardware that was already built.

Didn't the service module (Zvezda?) go up before the FGB (Zarya? I might have gotten the names backwards). I see these reversed in your list?

Would the SSRMS really need its own ICLV (flight 11)? Maybe stack together with something small like a PMA?

Does either the Logistics Transport Vehicle allow for significant return mass. Is such a capability even actually needed?

Does Soyuz assume a greater role in this scheme or are the short duration construction crews carried up by the CTV?

Those are the minor details that I said would worked if this were real

It is not that " too many people say the ISS couldn't have been built without the shuttle." It is what are we going to do without "RMS, airlock, large crew and payload bay i.e. the "shuttle paradigm". This exercise is to show that isn't needed. I might put something together to show how the non ISS missions could be done without the shuttle.

Very interesting. I'd like to add that Roskosmos has known how it'll be building the ISS without shuttle. Roskosmos has had various plans. Of course without shuttle we'll get less benefit from the station.

vt_hokie - 21/2/2008 12:54 PMAs an aside, I seem to recall that the Skylab display at the Air & Space Museum is actual flight hardware. Is that correct?

If you consider that two flight-quality Skylabs were built, and the "real deal" disintegrated into fragments over the Indian Ocean and Western Australia in 1979. The 2nd (unused) Skylab is what you see at the Air & Space Museum.

Yeah skylab, some 75 tons in one launch! Always erks me when i see the payload stats on the next supply/assembly mission to the ISS. STS-122 took only 17,311 kg, but then you have to factor the weight of orbiter etc. Jim is right. Imagine the size of the beast that could be orbiting now if we have used 10 or more Saturn INT-21 launches! Such a waste to scrap the Saturn.

One more thing: We do a lot of shuttle-bashing these days as in "all the bad decisions that were taken back then", "if we only had kept the Saturns" etc. We know that now, but probably we had to go through that experience to learn that the shuttle paradigm does not work.

Regardless of the failure of the shuttle paradigm, the Saturn V was unaffordable. There is no way the production line could have been kept open on the lean NASA budgets of the mid-70s, even if the shuttle had not been developed.

Another thing came to my mind yesterday: also during STS-120 they relocated the P6 truss.It was first detached by the station arm, then given to the shuttle arm, then the station arm rode to the end truss to take the P6 back and put it in its place.Apparently the P6 was too heavy to just drive on the SSRMS to the end of truss.

So I guess they would have needed two station arms.

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Don't ever become a pessimist... a pessimist is correct oftener than an optimist, but an optimist has more fun, and neither can stop the march of events. - Robert Heinlein

And "failure of the shuttle paradigm" should always be qualified in two ways:

1) It "failed" as a version 1.0. No other complex transportation technology has ever come close to an operational/economic sweet spot in its first and only iteration. That we blame the shuttle for failing to do so says more about hyper-inflated expectations than it does about either the paradigm or the specific design.

2) It "failed" at the painfully low flight rates that were inevitable without sustained Apollo-or-higher budgets. (And by the standards of aviation even the upper reaches of Mathematica fantasy count as "painfully low"). It's fun and easy to tout the obvious economies of reusability ("if we threw away a jetliner after every flight...") It's painful and hard to accept just how many flights it takes for those economies to overcome the enormous up-front costs.

From where I sit, the only paradigm that demonstrably "failed" was that of "Here's a technology path that's inherently incremental, slow and very very expensive. We'll attempt it in one big jump, fast, and on the cheap. Then we'll spend 37 years second-guessing the design as if that were the heart of the problem."

The whole issue of affordability ignores the relativism of the issue. Suppose you had a vehicle that could put 500 mT in LEO, and that the amortised cost of each launch (infrastructure, development, production, and payload costs) was $10bln. Let's say you wanted to launch one a month. How much Iraq War does that buy you? How much welfare entitlement? What percentage of the Federal budget is that? I could swear the deepest and most cherished desire of the American taxpayer is to see their hard-earned money wasted in as many ways as possible, and space exploration is just not sufficiently useless and wasteful.

And "failure of the shuttle paradigm" should always be qualified in two ways:

1) It "failed" as a version 1.0. No other complex transportation technology has ever come close to an operational/economic sweet spot in its first and only iteration. That we blame the shuttle for failing to do so says more about hyper-inflated expectations than it does about either the paradigm or the specific design.

2) It "failed" at the painfully low flight rates that were inevitable without sustained Apollo-or-higher budgets. (And by the standards of aviation even the upper reaches of Mathematica fantasy count as "painfully low"). It's fun and easy to tout the obvious economies of reusability ("if we threw away a jetliner after every flight...") It's painful and hard to accept just how many flights it takes for those economies to overcome the enormous up-front costs.

From where I sit, the only paradigm that demonstrably "failed" was that of "Here's a technology path that's inherently incremental, slow and very very expensive. We'll attempt it in one big jump, fast, and on the cheap. Then we'll spend 37 years second-guessing the design as if that were the heart of the problem."

"shuttle paradigm" for the context of this discuss is not the reusability nor flight rate aspects of the design but the design features wrt to payloads/missions (RMS, airlock, large crew and payload bay i)

How would they have repaired the tear in one of the solar arrays on the P6 without the Shuttle's OBSS?I remember there wasn't an easy way to do that.

I'm not sure they could have you could try and use the CTV and hover over the damaged section but you'll have issues of jet wash from the RCS thrusters.Maybe you could attempt said repair with something like the MMU but it will be a lot more dangerous then using the OBSS.

As for what would be the workhorse if the shuttle was never built I'd say likely Saturn derived hardware such as the Saturn IB with the SASSTO as the upper stage and the Saturn V-B a stage and a half to orbit Saturn with a 50,000lbs payload along with the closely related Saturn V-C 179,000lbs into LEO.These would have been small enough to be affordable but not so small as to be useless for station construction the V-C might have offered a very good cost per ton of payload delivered better then anything presently flying.

I agree version 1.0 of anything complex is always bug ridden ,clunky and expensive.How many iterations did it take to arrive at the airliners we have today or even arrive at a marketable hybrid car I think the auto companies spent billions.

On the subject of flight rate it seems the bugs in the shuttle were one thing keeping the flight rate so low it was often grounded for months even years on end while the issue was resolved that and orbiter processing taking three months.

Who knows maybe a 2.0 version of the shuttle would deliver many of the promises of the first.

Sid454 - 3/3/2008 2:57 PM On the subject of flight rate it seems the bugs in the shuttle were one thing keeping the flight rate so low...

They certainly contributed, but even with everything "working as designed" it couldn't get anywhere near a flight rate that would have made economic sense. NASA (seeing the writing on the wall by 1977-78 or so) never created the facilities (or contracted for the SRB or ET production rates) that would have been needed; for that matter, there was no realistic prospect of enough payloads even under "everything goes on STS" rules.

Understand, I'm not defending the Shuttle. I'm saying that the reasons it fell far short of the "affordable space truck" touted c. 1972 were deeper and broader than those usually cited: that given how different a reusable had to be from what we'd done before (and the unavoidable impact on payload of reusability), nothing was going to hit the sweet spot within a decade, on any budget; it would have taken (and will still take now) repeated "non-operational" iterations to even get close.

I know I sound like a broken record on this topic, but I think it's profoundly important. We screwed up with STS because we vastly underestimated how hard it would be, how much it would cost, and how long it would take to get from ELVs to CATS. So when I look around today and see that 90% of what passes for "analysis" boils down to "we coulda done it with another few billion" or "we coulda done it with this other design" or "we coulda done it if NASA hadn't had a mysterious attack of the stupids after Apollo"... or in the latest version, "private enterprise is just about to do it because it isn't NASA"...

What I see is yet another round of delusion rather than what I want: an honest appraisal of the scope of the challenge, followed by an honest commitment to buckle down and slowly, patiently, incrementally DO IT.

"shuttle paradigm" for the context of this discuss is not the reusability nor flight rate aspects of the design but the design features wrt to payloads/missions (RMS, airlock, large crew and payload bay i)

I can see the use of the above items, I just do not see why they have to be brought back to Earth each time.

modavis - 3/3/2008 8:04 PMWhat I see is yet another round of delusion rather than what I want: an honest appraisal of the scope of the challenge, followed by an honest commitment to buckle down and slowly, patiently, incrementally DO IT.

Because I want the whole nine yards: permanent moon base, men to Mars, SPSats and SPSat-sized telescopes, planetary probes on a much greater scale, ever-increasing ISRU -- and without CATS I don't think they're going to happen. Broadly speaking, I see three courses:

1) Sit back and wait for order-of-magnitude tech breakthroughs to make space much cheaper (or wait for sheer economic growth to make it relatively cheaper)

2) Keep attempting to replicate 1957-1969: make expensive "lunges" at thousands of dollars per kg, find them unsustainable, and then sit around for decades mourning the loss of Vision and wanking over Powerpoint designs

3) Take CATS seriously, accept that neither tax support nor private demand is enough to get us there (i.e. make it self-financing) in less than several decades, and go for it methodically through X-programs while continuing to use (and modestly improve) ELVs for operational purposes.

Because I want the whole nine yards: permanent moon base, men to Mars, SPSats and SPSat-sized telescopes, planetary probes on a much greater scale, ever-increasing ISRU -- and without CATS I don't think they're going to happen. Broadly speaking, I see three courses:

1) Sit back and wait for order-of-magnitude tech breakthroughs to make space much cheaper (or wait for sheer economic growth to make it relatively cheaper)

2) Keep attempting to replicate 1957-1969: make expensive "lunges" at thousands of dollars per kg, find them unsustainable, and then sit around for decades mourning the loss of Vision and wanking over Powerpoint designs

3) Take CATS seriously, accept that neither tax support nor private demand is enough to get us there (i.e. make it self-financing) in less than several decades, and go for it methodically through X-programs while continuing to use (and modestly improve) ELVs for operational purposes.

"shuttle paradigm" for the context of this discuss is not the reusability nor flight rate aspects of the design but the design features wrt to payloads/missions (RMS, airlock, large crew and payload bay i)

I can see the use of the above items, I just do not see why they have to be brought back to Earth each time.

"shuttle paradigm" for the context of this discuss is not the reusability nor flight rate aspects of the design but the design features wrt to payloads/missions (RMS, airlock, large crew and payload bay i)

I can see the use of the above items, I just do not see why they have to be brought back to Earth each time.

too expensive

The fuel for a station keeping ion engine is going to cost a lot less than launching the equipment about 10 times. The tool box satellite would only be visited when the tools are needed.

I am surprised that there actually is discussion if that is possible. Of course it’s possible since the Russians built Mir that way. Put airlock and robotic arm on the first module you launch and you can do just about anything that shuttle can do. You only need to deliver payload close enough that robotic arm can grab it.

I would probably add specialized tug that could go and pick up launched pieces to enable the payloads to be dumber (cheaper), but even that is not really needed.

One thing is certain. It would not take decades to put everything into LEO. You could put them on different rockets (Delta, Atlas, Ariane, Proton, Sea launch, Soyuz,..), launch them and have everything in space within a year. And if something explodes, well.. shuttle can also explode, so that is a non-issue. It’s actually better, since there would be no humans onboard and you are not tied to one launch system. If Delta fails you launch everything on other rockets while you find and fix the problem.

ISS “required” Shuttle to assemble, because it was designed to “need” the Shuttle. It gave the Shuttle something to do, thus created a “need” for US taxpayers to pay for the Shuttle.

One possible way of constructing the station with an Apollo class spacecraft (in the 1980's or 90's had there been no Shuttle) would be to have a "Saturn 1C" (with an F1 type of engine) for basic taxi and unmanned logistics missions, and use a larger Saturn 2, with two F1 type of engines (AKA the Jarvis Rocket). Assuming an 80,000 lbs payload on the S2, the CM could do a transposition and docking maneuver and take the components to the station, rather than requiring the Russian method of each component having independant maneuvering capasities. This would also permit single payloads of 80,000 lbs to be parked until a CM docks to it, and ferries it to the station.

The fact that the S1 and the S2 LVs use the same engines and components would have greatly reduced the developement costs of a launch family.

This scenario fits in nicely with the Direct proposal, while the Ares V can practically launch a Skylab type facility in a single launch.

One possible way of constructing the station with an Apollo class spacecraft (in the 1980's or 90's had there been no Shuttle) would be to have a "Saturn 1C" (with an F1 type of engine) for basic taxi and unmanned logistics missions, and use a larger Saturn 2, with two F1 type of engines (AKA the Jarvis Rocket). Assuming an 80,000 lbs payload on the S2, the CM could do a transposition and docking maneuver and take the components to the station, rather than requiring the Russian method of each component having independant maneuvering capasities.

Not a good concept.

1. the IB flew and IC would fly offloaded CSMs, with less propellants.

2. The point is not need a manned launch for every element. That is the shuttle paradigm which is trying to avoid. also it requires two launches for every element

3. Better yet look at #5 on my list . The SM tug could be reused a few times

I put myself in a mid 1970's mindset had NASA simply continued on without a Saturn V or Shuttle, but I'll heartily agree with you that not everything has to be manned and that the space station was simply put there to justify the shuttle, especially post Challenger when it was no longer to be used for commercial satellite launches.

Would it be feasilbe to construct a space station with a combination of a reusable winged LEO taxi for the people (think Kliper or HL-20 launched like DynaSoar) and then using a tug (think Parom or ATV propulsion section with a docking mechanism added to it) to transport modules to the construction side. The idea behind this is that the tug could be reused several times.This would be achieved by making the manned vehicle very light (it wouldn carry just enough fuel to deorbit itself from the insertion orbit in case of emergency). With a mass of say 12 mt it could be launched on a 24 mt launcher together with an external tank that would refuel the tug on everry manned mission. That way the tug would always carry modules in the 24 mt range just as the LV while the tug could be refueled regularly without additional launches.

EDIT: the tug could be simplyfied by having a seperate cargo docking mechanism from the people transfer docking mechanisms we have to day, it would be similiar to the one used on Athena+Gemini. I'd guess such a docking mechanism would a lot cheaper to build than when there is a requriement for a tunnel and a hatch.This way the tug could also reboost the station.

One thing is certain. It would not take decades to put everything into LEO. You could put them on different rockets (Delta, Atlas, Ariane, Proton, Sea launch, Soyuz,..), launch them and have everything in space within a year. And if something explodes, well.. shuttle can also explode, so that is a non-issue.

Yeah, it is an issue, Shuttle or otherwise - because loss of a module puts a *serious* crimp in your station.

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It’s actually better, since there would be no humans onboard and you are not tied to one launch system. If Delta fails you launch everything on other rockets while you find and fix the problem.

To some extent, yeah. Assuming all your modules were designed to the worst (vibration, 'G') case and all your modules were designed to fly on an adapter that's universal at the module end and custom designed at the booster end. It won't be cheap and it'll seriously cramp your design space though.

A big part of having a space station is for "outreach"- making it something that looks neat, that inspires awe. In order for john sixpack taxpayer to want to foot the bill, NASA projects have to have a "cool" factor. I actually have the ISS as my screensaver. The space shuttle allowed for the construction of the truss, which makes the ISS look good. With ELV construction, we would just have another gross looking MIR - a bunch of cans glued together with solar panels jutting out everywhere. So, I think there is something to be said for the job that has been done with the ISS. Each new amazing picture of the ISS on orbit gives NASA an extra fund raising boost, and in my opinion, this justifies the shuttle's added expense.

To some extent, yeah. Assuming all your modules were designed to the worst (vibration, 'G') case and all your modules were designed to fly on an adapter that's universal at the module end and custom designed at the booster end. It won't be cheap and it'll seriously cramp your design space though.

Incorrect1. Environments are not that much different among the same class vehicle

2. There are already common interfaces among Ariane, Zenit, Delta IV and Atlas V

3. "neat" looking is not a reason for building something. It doesn't give NASA a funding boost, much less the shuttle's added expense

Sure it is. I'd say that "being neat looking", or more generally "being cool" is one of the significant purposes of the ISS. It's not giving us much useful science. "Learning how to live in space" is the worst sort of circular reasoning. Sure, it provides a bunch of jobs in various states.

But in a significant way, it's a piece of art.

« Last Edit: 04/11/2009 05:29 PM by Chris Bergin »

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California 2008 - taking rights from people and giving rights to chickens.

Wubblie, the problem is that your basic presupposition is false. The "neatness" of the ISS has nothing to do with the Shuttle, but has to do with the design methodology undertaken by its constructor, NASA. An ISS built along the lines of this thread would look fundamentally the same as one built using the Shuttle, as the components and overall design decisions would be made under the same organization. The Shuttle is but a delivery vehicle for the components, and a platform to work on them; this thread shows that ELVs could undertake the delivery missions, and that the early ISS and other components could function as the platform.

MIR looked the way it did because of the decisions made by the Russians in its parts and overall design; indeed, the Russian portions of the ISS utilize similar parts and therefore share the same appearance. MIR looked the way it did because it was the outcome of a Russian process; ISS looks the way it does because it was the outcome of a NASA process, and that process would be the same even using alternate delivery and assembly methods. The Shuttle is not the difference between the two. The ISS would be just as awe inspiring built without it; it would look more or less the same even.

The truss is a component that is a fundamental aspect of NASA's ISS design, like the other modules, that is independent of the delivery vehicle. Alternate delivery methods would have been able to bring it to the ISS for assembly; the Shuttle is not a unique requirement for its inclusion in the ISS. The projects you mention are not on the same scale as the ISS requiring such a component and are subject to a different organizational process than that undertaken by NASA.

I would greatly recommend that you consider sticking around. This site is one of the rare aggregators of knowledgeable space commentary on the present internet. The reality is that much of the general thought on the topic of spaceflight is false or even absurd. A place like this allows for those notions to be held up to critique, to either stand on their own or be corrected. This can be withering to be on the end of, but it is a necessary environment to improve the state of thought on the subject.

Oh, It COULD have. I guess that is why no orbiting lab delivered by ELVs has had one, and the other two in planning- by China and ESA's ATV evolution, aren't considering it. But they COULD have. Nice point, I guess you proved me wrong.

Wrong, actually. The Chinese Tiangong-2 multi-module station (their Mir clone) is planned to have a horizontal truss for sensors and solar arrays extending out from the two lateral-mounted modules. The mechanics of assembling a truss are different using ELVs but it is possible. It is just that none of the ELV-launched space labs have used it... yet.

« Last Edit: 04/11/2009 05:29 PM by Chris Bergin »

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Over the past ~10 years NASA has spent $2B/year on ISS and $4B/year on the Shuttle whose almost exclusive job was to launch and assemble the ISS. Thus basically NASA has spent about $6B/year on ISS.

Following Jim’s thought, if NASA had designed basically the same ISS space station, but built all of the elements for aft mounting and launch on an expendable rocket NASA would have only needed to spend about $2B/year for launch: 4 annual EELV heavy launches + 2 annual OSP like crew launches.

With a human spaceflight savings of $2B/year there is a lot that NASA could have accomplished over the past decade, such as ISS utilization, more robust robotic lunar and Mars missions, technology development, fund exploration without requiring near impossible budget increases.

I just hope that 10 years from now we don’t find ourselves looking back and wondering what could have been if only NASA hadn’t spent $44B developing Ares I/Orion and who knows how many additional $10’s of billion on Ares V with the first crewed lunar mission still a future goal.

Most people believe that one must have a Saturn V or Ares V class rocket to launch a large space station volume. For ISS, each module was limited to about 4 m in diameter and ~100 m3 due to the Shuttle Orbiter’s cargo bay. This would be roughly equally true for a station element launched inside of a 5m payload fairing. One method to enable larger volumes is inflatable habitats such as being worked by Bigelow. Another option for expendable launchers (more challenging for Shuttle) is actually making the station module match the outer mould line of an expendable launch vehicle payload fairing, replacing the fairing itself. For current launch vehicles this enables a module with about 350 m3 volume, very favorable compared to Skylab’s 285 m3, MIR’s total volume of 350 m3 or ISS’s final total volume of 1,000 m3.

Another option for expendable launchers (more challenging for Shuttle) is actually making the station module match the outer mould line of an expendable launch vehicle payload fairing, replacing the fairing itself. For current launch vehicles this enables a module with about 350 m3 volume, very favorable compared to Skylab’s 285 m3, MIR’s total volume of 350 m3 or ISS’s final total volume of 1,000 m3.

The only drawback doing that is each module would need to be 'overbuilt' from a structural standpoint. It would not only need to withstand ELV launch vibrations and acoustics (both higher than within a Shuttle cargo bay), but also be self-supporting through the launch on top of a single payload attach mount.

It would not only need to withstand ELV launch vibrations and acoustics (both higher than within a Shuttle cargo bay),

Shuttle acoustics are higher due to the closer proximity of payload to the ground and engines

Interesting. I always figured the multiple layers of the payload doors + radiators and sheets of thermal protection fabric in the bay would act to dampen much of the 'outside' noise.

Fairings have acoustic blankets.

The SRB reverbing off the MLP when the shuttle is a few hundred feet up is the peak, I believe

The source energy for the shuttle is 6.8 mlb thrust. For Atlas 551 this is 2.4 mlb thrust and Delta IV HLV 2.0 mlb of thrust. also, the shuttle launch complexes have a lot more structures to reflect engine plume energy back up to the vehicle and its payload. Thus it makes perfect sense for the shuttle to have higher accoustic energy.

And "failure of the shuttle paradigm" should always be qualified in two ways:

1) It "failed" as a version 1.0. No other complex transportation technology has ever come close to an operational/economic sweet spot in its first and only iteration. That we blame the shuttle for failing to do so says more about hyper-inflated expectations than it does about either the paradigm or the specific design.

Bad excuse. This was known to Shuttle designers. They deluded themselves that they can pull it off.

And "failure of the shuttle paradigm" should always be qualified in two ways:

1) It "failed" as a version 1.0. No other complex transportation technology has ever come close to an operational/economic sweet spot in its first and only iteration. That we blame the shuttle for failing to do so says more about hyper-inflated expectations than it does about either the paradigm or the specific design.

Bad excuse. This was known to Shuttle designers. They deluded themselves that they can pull it off.

Every 1.0 system historically was buggy just because the shuttle was flawed does not mean RLV's in general are a flawed concept.

Considering the economic environment the shuttle program got started in they did have a hard sell to the public.

Though in retrospect the rev 1.0 shuttle should have been a smaller vehicle and the Saturn V and it's derivatives been kept for heavy lift.

But to pay for the shuttle NASA had to give into USAF demands which included a 3000 mile cross range and the ability to carry a 15 by 65 foot payload.

They knew about the flaws but likely hoped they would get funding to slowly rectify all the faults with the system.

Shuttle-C for example was an early attempt to regain the lost lift they used to have with Saturn.They didn't set out to make the shuttle a jack of all trades they really had no choice.Considering the demands they had to meet and the fact they had to finish it on half the original planned R&D budget they did pretty good.

I'm interested in the interaction between launch vehicles and tugs when constructing a space station without the shuttle. Jim has pointed out the need for attitude control of modules until the tug arrives. For short periods of time an upper stage might be able to do that. Is that good enough? And if not, is there some simple way to provide attitude control short of launching a tug together with the module?

And how about an L1 station? I'm thinking of using low-energy ballistic trajectories, so an off the shelf upper stage would be long dead by the time it arrived at L1. What would be the solution, some kind of long-duration mission kit or some simple "attitude control kit" if that is at all possible?

And how about an L1 station? I'm thinking of using low-energy ballistic trajectories, so an off the shelf upper stage would be long dead by the time it arrived at L1. What would be the solution, some kind of long-duration mission kit or some simple "attitude control kit" if that is at all possible?

Well the Soviet Salut-class and Almaz-class space lab modules all had their own RCS system. A lot depends if you wanted the module to carry their own RCS around for their entire service lives or whether they were only needed until they were docked onto a larger structure.

In the case of the latter, the simplest thing would be to launch the module with a small 'Service Module-Lite' that would be expended once the module is attached to the main structure.

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The time for words has passed; The time has come to put up or shut up!DON'T PROPAGANDISE, FLY!!!

Just for starters, if NASA had dropped most of the payload requirement from the Shuttle (which they didn't need), they wouldn't need USAF funding. A fluffier shuttle wouldn't need the special tiles of the TPS that were so hard to make and maintain. Jon Goff had a good article on what if the designers of the Shuttle had gone for a crew-only vehicle combined with the Saturn 1B. It's far cheaper and it covers most of the Shuttle's capabilities.

Just for starters, if NASA had dropped most of the payload requirement from the Shuttle (which they didn't need), they wouldn't need USAF funding. A fluffier shuttle wouldn't need the special tiles of the TPS that were so hard to make and maintain. Jon Goff had a good article on what if the designers of the Shuttle had gone for a crew-only vehicle combined with the Saturn 1B. It's far cheaper and it covers most of the Shuttle's capabilities.

Excellent article ! Can't help thinking that what Goff described looks - a bit - like the MAKS shuttle...

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For short periods of time an upper stage might be able to do that.

The more I look at it, the more I'm convinced that the Lockheed Agena could have done the job very well... Agena Service Module for space station assembly, then Agena Logistic Vehicle (MPLM/ ATV hybrid) riding to space atop a Delta 7000, Ariane 3, Atlas II or Titan II...

« Last Edit: 06/18/2009 05:00 PM by Archibald »

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One huge problem the Saturn line had was the fact it consisted of two vehicles with only the S-IVB as a common part.Though they considered dropping the IB and replacing everything with Saturn V derivatives and making the first stage partly reusable.The Saturn V-B could have made a good intern crew launch vehicle using one of the lifting body designs for a crew vehicle until a TSTO RLV was ready.http://en.wikipedia.org/wiki/Saturn_V-BAn alternative lower cost crew vehicle would have been big Gemini which is remarkably similar to the soviet TKS/VA spacecraft.http://www.astronautix.com/craft/bigemini.htmIt might have been a harder sell as it's less gee wizz then a space plane crew vehicle.The same S-ID from the V-B plus a cost reduced S-IVB or even SASSTO upper stage also could be used for station construction.The SASSTO is interesting in that it might be able act as a tug or at least provide attitude control until the tug gets the payload.

The Russian modules on ISS seem to be very cramped compared to the US side possibly due to lost volume for attitude control hardware and fuel tanks.Though even a Saturn INT-20 would have fairing volume to spare so it may not be too bad an issue to have a full RCS on the modules.

<p>And "failure of the shuttle paradigm" should always be qualified in two ways:</p><p> 1) It "failed" <strong>as a version 1.0. </strong>No other complex transportation technology has ever come close to an operational/economic sweet spot in its first and only iteration. That we blame the shuttle for failing to do so says more about hyper-inflated expectations than it does about either the paradigm or the specific design.</p>

But Shuttle designers knew that too, right?

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<p>2) It "failed" <strong>at the painfully low flight rates</strong> that were inevitable without sustained Apollo-or-higher budgets.

Was this a secret to NASA that Apollo-level budgets aren't to be expected anytime soon?

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<p>From where I sit, the only paradigm that demonstrably "failed" was that of "Here's a technology path that's inherently incremental, slow and very very expensive. We'll attempt it in one big jump, fast, and on the cheap. Then we'll spend 37 years second-guessing the design as if that were the heart of the problem."

That's why we should not do such huge jumps in R&D. One mistake, and we find forty years of HSF nearly wasted.

The program was initiated after NASA showed some briefing slides to Reagan that depicted a late Salyut station (I think it was Salyut 7). Those briefing slides are publicly available, but I'm not sure if they're online. I think they were reprinted in one of the Exploring the Unknown books.

Anyway, we're venturing far afield here, but to answer your question, I don't think the issue was size. Reagan did not say "build a space station that is larger than the Russian one." He simply agreed to a space station because the Soviets already had one. So simply having a US-led space station that allowed for both permanent presence and the participation of Western allies would have satisfied that basic requirement. That could have been done with a few modules and an expandable capability.

Unfortunately, the ball quickly got rolling and what NASA started to design was bigger than Mir, bigger than Skylab, included many modules, many launches, a lot of power, etc. Now they justified this in part because they said that they needed to do X-science missions and that required a sizeable volume with very low gravity. But they did that in a pretty sloppy and half-hearted way, and once they started building the ISS hardware (and _building_ stuff is what NASA engineers really wanted to do), then they started to blow the budget, and they started to axe the science. Was science really a justification, or just an excuse?

(SNIP)

So what could they have done differently? Start with something small, Salyut-sized, that could have been launched in a single shuttle mission. Keep the science goals modest (primarily longer-duration human spaceflight, not materials science). Get it up there and say "We now have a space station." After that, expand it gradually, add a European module, a Japanese module, etc. Then, if necessary, throw it all away and develop a bigger one. Had they followed this approach, they could have had a space station by the original timeline (1990) and gotten several years of operation out of it. By that time cooperation with the Russians would have become possible.

Longer duration Spacelab experiments. After all, you could do Spacelab experiments in, er, Spacelab. So if you could extend the flight duration a bit, you could get a month or two of experiments in Spacelab equivalent racks. That should have been easily accomplished with a couple of shuttle launches placing two modules in orbit.

I've long thought that this was what the US should have done. We should have taken the Russian approach of launching a core module and then adding to it as resources became available.

But you have to understand how NASA works and that starts with understanding that human spaceflight is essentially an engineering exercise. The engineers want to build something big and ambitious and challenging, because that's fun. They care little about what it will actually do, as long as that justifies building it in the first place.

So they establish a set of assumptions that are also big and ambitious. In the case of the space station, they decided that it would have a significant micro-g area, and it would also mount both Earth-viewing and astronomy sensors. And it could also have a construction/support role. All of this cried out for a very large station, and that's how Space Station Freedom was conceived.

But what then happened was that the engineering costs kept overrunning, and when that happened, they threw off the easiest things to discard, which were the things that were supposed to be added late in construction, i.e. all the science stuff that established the initial justification for the station (there's a pretty long list). That way, over a long period of time, what we ended up with was an engineering project, where all the time and effort is expended building and maintaining the station, and not actually _doing_ anything on it. After ten years of construction, the astronauts are able to perform three hours of experiments per _week_ on the ISS.

If the U.S. had instead taken the Soviet Salyut/Mir approach, they could have been conducting initial science experiments from the start and adding to that as the station grew. Yeah, you can argue that the science would not have been terribly ambitious, but 70% (or even 40%) of something is better than 100% of nothing.

(Alt-history is just speculation, but its fun at times).I'm writting an alternative history (Voyage style) where the shuttle is canned by Nixon OMB late 1971 and get replaced by Big Gemini with the main effort shifting back to a space station. This space station is very much a "Mir on steroids" launched by a handful of Saturn IB circa 1980. The Agena ends up playing a very important role in this history, it becomes NASA own FGB.

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...I've long thought that this was what the US should have done. We should have taken the Russian approach of launching a core module and then adding to it as resources became available.

But you have to understand how NASA works and that starts with understanding that human spaceflight is essentially an engineering exercise. The engineers want to build something big and ambitious and challenging, because that's fun. They care little about what it will actually do, as long as that justifies building it in the first place.

So they establish a set of assumptions that are also big and ambitious. ...

But what then happened was that the engineering costs kept overrunning, and when that happened, they threw off the easiest things to discard, which were the things that were supposed to be added late in construction, i.e. all the science stuff that established the initial justification for the station (there's a pretty long list). That way, over a long period of time, what we ended up with was an engineering project, where all the time and effort is expended building and maintaining the station, and not actually _doing_ anything on it. After ten years of construction, the astronauts are able to perform three hours of experiments per _week_ on the ISS....

...

Wow... A lot of truth in those statements from Blackstar.

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Why is everyone so enamored with Big Gemini? Any plausible alternative history should use Apollo hardware.

Jim, I don't get the complaint. Googling around, it appears that Big Gemini was designed to use several launch vehicles including the Saturn 1 series (1B, 1C) and be compatible with Apollo missions. What makes it not Apollo hardware?

Why Big Gemini over Apollo ? From the documents of the era - late 1971 reports from Nixon PSAC and OMB - its really looks as if the fallback option if no shuttle is Big Gemini before Apollo. The distinction between Apollo and Big Gemini is subtile. Apollo is the minimum option that preserves manned spaceflight, period. Big Gemini is more than that. It is the least expensive space station logistic vehicle. Big Gemini is superficially similar to a shuttle, in the sense that it features a) a 6-9 men cockpit that land on a runway b) a large cargo section (although not reusable, unlike the shuttle)

In some way Big Gemini was included in the vast arrays of shuttle options - shuttle in the broad sense of the word, read, manned space station logistic vehicle. Apollo was not. It is not an insult to Apollo to say that it was build with lunar missions in mind, not Earth orbit space station crew and ferry vehicle.

In depends what program for NASA if no shuttle. The high-end might have been Big Gemini to a new space station; the low-end, Apollo to nowhere, kind of AAP 28 or 45 days Earth survey missions.

From The space shuttle decision, chapter 4

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The options would bear comparison with those favored by Paine; but whereas Paine started with the current budget and hoped to go upward, the BoB staff started at the FY 1970 level and considered the consequences of tilting sharply downward.

(snip)

Two other options, at $2.5 billion, also permitted flight of Skylab with its three visits, along with the six Apollos [NOTE - the six lunar landings]. There could even be a space station in 1980, with Titan III-Gemini for logistics. However, there would be no space shuttle.

Of course we know from 30 years of shuttle experience that mixing crew and cargo is just silly. So Big Gemini was certainly not an ideal vehicle either !

« Last Edit: 12/22/2010 06:43 PM by Archibald »

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What about the modules, would they be like the current NASA ISS modules brought by an expendable tug to ISS?, would the module + tug fit in an Atlas or Delta ?. also without the shuttle the modules would be different since the current modules are spacelab heritage. Another thing is the truss, seems to me like its really inefficient, since there is no shuttle the truss would be more like a line of couple of unpressurized service modules with smaller booms (like that on Mir) holding the panels.

1. What about the modules, would they be like the current NASA ISS modules brought by an expendable tug to ISS?, would the module + tug fit in an Atlas or Delta ?.

2. also without the shuttle the modules would be different since the current modules are spacelab heritage.

3. Another thing is the truss, seems to me like its really inefficient, since there is no shuttle the truss would be more like a line of couple of unpressurized service modules with smaller booms (like that on Mir) holding the panels.

The exercise was to show that the shuttle is not needed for construction of a space station. Yes, without the shuttle, the design would be different.

1. Yes, that was the point of the exercise and yes

2. no, they aren't Spacelab heritage. they are new design.

3. How is it inefficient? There many more systems in the truss other than solar arrays.

1. What about the modules, would they be like the current NASA ISS modules brought by an expendable tug to ISS?, would the module + tug fit in an Atlas or Delta ?.

2. also without the shuttle the modules would be different since the current modules are spacelab heritage.

3. Another thing is the truss, seems to me like its really inefficient, since there is no shuttle the truss would be more like a line of couple of unpressurized service modules with smaller booms (like that on Mir) holding the panels.

The exercise was to show that the shuttle is not needed for construction of a space station. Yes, without the shuttle, the design would be different.

1. Yes, that was the point of the exercise and yes

2. no, they aren't Spacelab heritage. they are new design.

3. How is it inefficient? There many more systems in the truss other than solar arrays.

And without the shuttle, would there be need for workpods (robotic on manned) or just a couple of arms or a arm mounted on a rail would work too?.Also cargo upmass could be served by an expendable cargo ship the size of a module & downmass with a cargo capsule, more like big apollo than big gemini.

5. Service Module with ARAD or OMV – could be derived from #2 but smaller. It provides attitude control, power and some propulsion to a launch package. Just what is needed to bring a launch package from insertion orbit to the ISS